JP3712682B2 - Residual toner recovery device for image forming machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention removes residual toner adhering to the peripheral surface of a toner image forming body such as a photosensitive member and an intermediate transfer member in an image forming machine such as a printer, a copying machine, and a facsimile, and collects the removed residual toner. The present invention relates to a residual toner collecting device.
[0002]
[Prior art]
In image forming machines such as printers, copiers, and facsimiles, a cleaning mechanism that removes residual toner adhering to the peripheral surface of a toner image forming body such as a photosensitive member or an intermediate transfer member, and the cleaning mechanism removes the residual toner. A residual toner collecting device including a residual toner collecting container for containing the residual toner and a residual toner carrying mechanism for carrying the residual toner removed by the cleaning mechanism to the residual toner collecting container is provided. The residual toner transport mechanism is disposed in the transport path, a residual toner dropping path for dropping the residual toner removed by the cleaning mechanism, a transport path connecting the residual toner drop path and the residual toner collection container, and the transport path. It comprises a conveying screw having spiral blades formed on the peripheral surface of the rotating shaft, and the residual toner dropped through the residual toner dropping passage is conveyed to the residual toner collecting container along the conveying path by the conveying action of the conveying screw. It is like that.
[0003]
Further, a sweep roller having an elliptical cross section is provided in the vicinity of the connection portion with the conveyance path in the residual toner dropping path, and the residual toner that has fallen into the residual toner falling path due to pressure propagation caused by the rotation of the sweep roller is sent to the conveyance path. Technology is used. However, in the case of the sweep roller having an elliptical cross section, when a large amount of residual toner adheres to the peripheral surface, a pressure difference due to the difference between the long side and the short side does not occur, and the toner conveying force due to pressure propagation is reduced. In order to solve this problem, residual toner adhered by pressing the tip of a scraper made of a flexible control member such as a synthetic resin film such as a polyethylene terephthalate (PET) film to the circumferential surface on the return direction of the sweep roller in the rotational direction is removed. Scraping technology has also been put into practical use. The scraper functions as a backflow prevention valve that prevents the backflow of toner due to the action of the sweep roller returning to the rotation direction.
[0004]
[Problems to be solved by the invention]
Thus, when the sweep roller is arranged in the vicinity of the connection portion with the conveyance path in the residual toner dropping path, the flow path area of the conveyance path is narrow or the conveyance screw is disposed in the conveyance path. When the toner conveying capability is low, toner accumulates between the sweep roller and the conveying path in the residual toner dropping path. As a result, the internal pressure of the passage where the rotation direction return side of the sweep roller is increased, the scraper is pushed out and reversed to the sweep direction of the sweep roller, and the toner flows backward in a large amount or the rotation direction of the sweep roller. There arises a problem that the passage where the sweep-out side is located is blocked.
[0005]
The present invention has been made in view of the above-mentioned facts, and the main technical problem thereof is that the sweep roller is maintained while scraping performance of the toner attached to the sweep roller disposed in the residual toner dropping passage is maintained. It is an object of the present invention to provide a residual toner recovery device for an image forming machine including a scraper that can suppress an increase in internal pressure of a residual toner dropping passage where a rotation direction return side is located.
[0006]
[Means for Solving the Problems]
In order to solve the main technical problem, according to the present invention, a cleaning mechanism that removes residual toner adhering to the peripheral surface of a toner image forming body, and a residual that contains residual toner removed by the cleaning mechanism are provided. A toner collection container; and a residual toner conveyance mechanism that conveys the residual toner removed by the cleaning mechanism to the residual toner collection container, and the residual toner conveyance mechanism drops the residual toner removed by the cleaning mechanism. In a residual toner collecting device of an image forming machine, comprising: a residual toner dropping path; and a conveying path that connects the residual toner falling path and the residual toner collecting container;
The residual toner transport mechanism includes a sweep roller disposed in the vicinity of a connection portion of the residual toner falling passage with the transport passage, an elliptical cross section, and a base end portion attached to an inner wall of the residual toner falling passage. Is provided with a scraper made of a flexible member disposed in pressure contact with the circumferential surface on the return direction side of the sweep roller, and the scraper is provided on a portion other than the contact portion with the sweep roller. A notch is formed,
A residual toner recovery device for an image forming machine is provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of a residual toner recovery device for an image forming machine constructed according to the present invention will be described below with reference to the accompanying drawings.
[0008]
FIG. 1 shows a schematic cross-sectional view of a laser beam printer as an image forming machine equipped with a residual toner collecting apparatus constructed according to the present invention.
The illustrated laser beam printer includes a rectangular parallelepiped housing 2 made of synthetic resin. In the substantially central portion of the housing 2, there is a space between a front side plate and a rear side plate made of a metal plate (not shown) arranged in the housing 2 at a predetermined interval in the front-rear direction (direction perpendicular to the paper surface in FIG. 1). A photosensitive drum 3 as a toner image forming member is rotatably disposed. The photosensitive drum 3 is driven to rotate by sequentially passing through a charging area, an electrostatic latent image forming area, a developing area, an image transfer area, and a cleaning area in a direction indicated by an arrow by a gear transmission (not shown). Around the photosensitive drum 3, a charging corona discharge device 4 is provided in a charging area, a developing device 5 is provided in a developing area, an intermediate transfer body 6 as a toner image forming body is provided in an image transferring area, and a photosensitive drum is provided in a cleaning area. Each of the cleaning mechanisms 7 is provided. In the illustrated embodiment, the developing device 5 includes a yellow toner developing unit 5a, a magenta toner developing unit 5b, a cyan toner developing unit 5c, and a black toner developing unit 5d. Further, the intermediate transfer member 6 is connected to the front and rear side plates disposed at a predetermined interval in the front-rear direction (direction perpendicular to the paper surface in FIG. 1) in the housing 2 in the same manner as the photosensitive drum 3. It is rotatably arranged between them and is driven to rotate in the direction indicated by the arrow by a gear transmission (not shown). A cleaning mechanism 8 for the intermediate transfer member is disposed at the lower left portion of the intermediate transfer member 6 in FIG. The cleaning mechanism 7 and the cleaning mechanism 8 may have a known configuration, and include a cleaning fur brush, a cleaning blade, and a conveying screw in cleaning cases 71 and 81, respectively.
[0009]
A laser unit 9 serving as an electrostatic latent image forming unit is disposed in the upper part of the housing 2. The laser unit 9 projects laser light based on image information output from a computer, for example, onto the peripheral surface of the photosensitive drum 3 in an electrostatic latent image forming area between the charging area and the developing area. In addition, a secondary transfer roller 10 is disposed below the intermediate transfer body 6 in the lower part of the housing 2, and is conveyed downstream of the secondary transfer roller 10 (left side in FIG. 1). A belt mechanism 11 and a fixing unit 12 are provided.
[0010]
Next, the operation of the laser beam printer described above will be briefly described.
While the photosensitive drum 3 is rotated in the direction indicated by the arrow, the charging corona discharger 4 charges the photosensitive layer of the photosensitive drum 3 to a specific polarity. Next, laser light is projected onto the photosensitive drum 3 from the laser unit 9 in the electrostatic latent image forming area between the charging area where the charging corona discharger 4 is disposed and the developing area where the developing device 5 is disposed. Then, an electrostatic latent image corresponding to the image information is formed on the peripheral surface of the photosensitive drum 3. Thereafter, the developing device 5 causes toner to act on the electrostatic latent image on the photosensitive drum 3 to visualize the electrostatic latent image. The toner image formed on the photosensitive drum 3 in this way is transferred to an intermediate transfer member 6 as a toner image forming member. In the case of color printing, the photosensitive drum 3 is charged by the corona discharger 4 for charging for each color, the exposure by the laser unit 9, the developing unit 5a for yellow toner, the developing unit 5b for magenta toner, and the developing unit for cyan toner. Development is performed by the developing unit 5d and the black toner developing unit 5d, and is transferred to the intermediate transfer member 6 each time. As a result, a multicolor toner image corresponding to the image signal for one sheet is transferred to the intermediate transfer body 6.
[0011]
On the other hand, the sheet P fed from a sheet feeding device (not shown) is temporarily stopped by a pair of registration rollers (not shown), and the intermediate transfer member 6 is timed with the intermediate transfer member 6 to which the toner image is transferred as described above. And the secondary transfer roller 10 are conveyed to a secondary transfer area facing each other. A toner image formed on the peripheral surface of the intermediate transfer member 6 by the action of the transfer roller 10 is transferred to the surface of the paper P conveyed to the secondary transfer area. The sheet P on which the toner image has been transferred is peeled off from the intermediate transfer member 6 and conveyed to the fixing unit 12 by the conveying belt mechanism 11, where the toner image is heated and fixed on the surface of the sheet and then discharged out of the housing 2. Is done.
[0012]
The residual toner adhering to the surface of the photosensitive drum 3 after the toner image is transferred from the photosensitive drum 3 to the intermediate transfer body 6 as described above is removed by the cleaning mechanism 7. On the other hand, residual toner adhering to the surface of the intermediate transfer body 6 after the toner image is transferred from the intermediate transfer body 6 to the paper P is removed by the cleaning mechanism 8. Hereinafter, the residual toner collecting device removed by the cleaning mechanism 7 and the cleaning mechanism 8 will be described with reference to FIGS.
[0013]
The residual toner recovery device 20 in the illustrated embodiment includes a residual toner recovery container 21 for storing residual toner removed by the cleaning mechanism 7 and the cleaning mechanism 8, and residual toner removed by the cleaning mechanism 7 and the cleaning mechanism 8. A residual toner transport mechanism 30 for transporting the toner to the toner recovery container 21 is provided. The residual toner collection container 21 is formed of an appropriate synthetic resin, and a joint portion 212 including a residual toner introduction port 211 is provided on the upper portion thereof. This joint portion 202 is connected to a connection portion, which will be described later, of the residual toner transport mechanism 30.
[0014]
The residual toner transport mechanism 30 includes a casing 31 including a transport path 310 extending in a direction perpendicular to the axial direction of the cleaning mechanism 7 and the cleaning mechanism 8 below the cleaning mechanism 7 and the cleaning mechanism 8. The casing 31 includes a first casing member 32 and a second casing member 33 that are formed of an appropriate synthetic resin.
[0015]
The first casing member 32 includes a receiving portion 321 that fits the inner portion of the cleaning case 81 of the cleaning mechanism 8 on the upper side in FIG. The receiving portion 321 is formed with a residual toner dropping passage 322 that communicates the toner discharge port 811 formed in the inner portion of the cleaning case 81 and the conveyance passage 310. On the other hand, the second casing member 33 includes a connecting pipe portion 331 that is connected to the rear portion of the cleaning case 71 of the cleaning mechanism 7 on the upper side in FIG. The connecting pipe portion 331 is formed with a residual toner dropping passage 332 that communicates a toner discharge port (not shown) formed in the inner portion of the cleaning case 71 with the conveyance passage 310. Further, the second casing member 33 includes a connection portion 333 that connects to the residual toner collecting container 20 on the lower side in FIG. 2 on the connection side with the first casing member 32. The connecting portion 333 is formed with a residual toner discharge port 334 that communicates with the conveyance path 310 between the residual toner dropping passages 322 and 332. In addition, the 2nd casing member 33 is formed of the two members divided | segmented by the surface perpendicular | vertical with respect to the said conveyance path 310, as shown in FIG.
[0016]
A conveyance path 34 formed by the first casing member 32 and the second casing member 33 is provided with a conveyance screw 34 formed of an appropriate synthetic resin. The conveying screw 34 includes a rotation shaft 341 and a first spiral blade 342 and a second spiral blade 343 formed on the peripheral surface of the rotation shaft 341. A support portion 345 having a non-circular connecting hole 344 is provided at one end portion (left end portion in FIG. 2) of the rotation shaft 341, and the support bush 345 is mounted on the first casing member 32. 35 is rotatably supported. On the other hand, the other end portion (right end portion in FIG. 2) of the rotating shaft 341 is rotatably supported by a bearing bush 36 attached to the second casing member 33. In addition, a snap ring 37 for retaining is attached to the right side of the bearing bush 36 of the rotating shaft 341 in FIG.
[0017]
The first spiral blade 342 and the second spiral blade 343 formed on the peripheral surface of the rotating shaft 341 are formed so that the spiral winding directions are opposite to each other. The first spiral blade 342 is formed from the left end portion of the rotating shaft 341 in FIG. 2 to a position reaching the substantially central portion of the residual toner discharge port 334, and the second spiral blade 343 is illustrated in FIG. 2 of the rotating shaft 341. It is formed from the right end portion to a position reaching the substantially central portion of the residual toner discharge port 334. The conveying screw 34 configured in this manner is connected to a connecting hole 344 formed in a support portion 345 provided at one end of the rotating shaft 341 by connecting a driving shaft of a driving mechanism (not shown) with an arrow in FIG. It is driven to rotate in the direction shown. The first spiral blade 342 constituting the conveying screw 34 rotating in the direction indicated by the arrow moves the residual toner that has fallen into the conveying path 310 from the toner discharge port 811 of the cleaning mechanism 8 through the residual toner dropping path 322 in FIG. In other words, the toner is conveyed toward the residual toner discharge port 334. On the other hand, the second spiral blade 343 causes the residual toner that has fallen from the toner discharge port (not shown) of the cleaning mechanism 7 to the conveyance path 310 through the residual toner drop passage 332 toward the left side, that is, the residual toner discharge port 334 in FIG. Transport. As described above, the residual toner dropped into the conveyance path 310 through the residual toner dropping passages 322 and 332 is left as a residual toner discharge port 334 by the first spiral blade 342 and the second spiral blade 343 constituting the conveyance screw 34, respectively. And is discharged from the residual toner discharge port 334 to the residual toner collection container 20.
[0018]
The residual toner collecting device in the illustrated embodiment includes a sweep roller 40 disposed in the vicinity of the connection portion with the conveyance path 310 in the residual toner dropping path 332. The sweep roller 40 has an elliptical cross section, and a shaft hole 401 and a large-diameter driving hole 402 formed continuously with the shaft hole 401 are formed at the center. An internal spline 402 a is formed on the inner peripheral surface of the drive hole 402. The sweep roller 40 configured as described above is driven to rotate in a direction indicated by an arrow in FIG. 3 by a drive shaft 41 disposed in parallel with the transport screw 34 disposed in the transport path 310. The drive shaft 41 is spline-fitted with a support portion 411 formed at the left end portion in FIG. 2 and an internal spline 402a formed in the drive hole 402 formed on the right side of the support portion 411 in FIG. A second shaft portion 412 having a tooth spline 412a; a first shaft portion 413 formed on the right side of the second shaft portion 412 in FIG. 2 and fitted in the shaft hole 401; and the first shaft The portion 413 includes a gear mounting portion 414 formed on the right side in FIG. The drive shaft 41 configured as described above is disposed through the connecting pipe portion 331, and the support portion 411 is rotatably supported by the second casing member 33 via the bearing bush 42. The drive gear 43 is mounted on the gear mounting portion 414 of the drive shaft 41, and the shaft portion 431 of the drive gear 43 is rotatably supported by the second casing member 33 via the bearing bush 44. The drive gear 43 is connected to a drive mechanism (not shown).
[0019]
The residual toner collecting device in the illustrated embodiment includes a scraper 45 that scrapes off toner adhering to the peripheral surface of the sweep roller 40 as shown in FIG. The scraper 45 is formed of a flexible control member such as a synthetic resin film such as a polyethylene terephthalate (PET) film, and its base end 451 is attached to the inner wall 332a of the residual toner dropping passage 332 by a double-sided adhesive tape. The tip portion 452 is disposed in pressure contact with the circumferential surface of the sweep direction return side 40 a of the sweep roller 40. As shown in FIG. 4, the scraper 45 has notches 453 and 453 formed on both sides of the intermediate portion. The cutouts 453 and 453 may be provided in a portion other than the tip portion that contacts the circumferential surface of the sweep roller 40, and may be a hole such as a circle or a rectangle.
[0020]
Next, the operation of the above-described sweep roller 40 and scraper 45 will be described mainly based on FIG.
When the sweep roller 40 rotates in the direction indicated by the arrow, the residual toner that has been removed by the cleaning mechanism 8 and dropped in the residual toner dropping passage 332 is swept downward by the rotational direction sweeping side 40b of the sweep roller 40 and is transported. It is sent to 310. On the other hand, when the surface that has been swept out by the rotation of the sweep roller 40 reaches the return side 40a, the toner adhering to the peripheral surface is scraped off by the scraper 45. Accordingly, it is possible to prevent a decrease in toner conveyance force due to a large amount of residual toner adhering to the peripheral surface of the sweep roller 40. In addition, when the conveyance amount by the sweep roller 40 becomes larger than the conveyance amount of the conveyance screw 34 disposed in the conveyance path 310, the internal pressure of the passage where the return side 40a of the sweep roller 40 is located increases. When the scraper 45 has the conventional configuration, the internal pressure reverses as shown by a broken line, causing a problem that the toner flows backward in a large amount or blocks the passage where the sweeping side 40b of the sweep roller 40 is located. . However, in the illustrated embodiment, notches 453 and 453 are formed on both sides of the intermediate portion of the scraper 45. Therefore, by allowing the backflow of a part of the toner through the notches 453 and 453, the scraper 45 is provided. Is prevented from occurring, and a stable conveying force for the residual toner can be obtained. Note that the scraper 45 is not provided with a notch at the tip that contacts the circumferential surface of the sweep roller 40, so that the scraping performance of the toner adhering to the circumferential surface of the sweep roller 40 is maintained.
[0021]
As described above, the residual toner collecting device configured according to the present invention has been described based on the embodiment applied to the color laser beam printer including the intermediate transfer member. However, the present invention is not limited to the embodiment, and the copying is performed. The present invention can be applied to various image forming machines such as a printer and a facsimile.
[0022]
【The invention's effect】
The residual toner collecting device for an image forming machine according to the present invention comprises a flexible member that is disposed in the residual toner dropping passage and has one end pressed against the circumferential surface on the return side in the rotational direction of an elliptical sweep roller. Since the scraper has a notch formed in a portion other than the contact portion with the sweep roller, when the internal pressure of the passage where the return side of the sweep roller is increased, one part of the toner is passed through the notch formed in the scraper. The reverse flow of the part prevents the scraper from being reversed, and a stable conveying force for the residual toner can be obtained. Note that the scraper is not provided with a notch at the tip that contacts the circumferential surface of the sweep roller, so that the scraping performance of the toner adhering to the circumferential surface of the sweep roller is maintained.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a laser beam printer as an image forming machine equipped with a residual toner collecting device constructed according to the present invention.
FIG. 2 is a cross-sectional view of a main part of a residual toner recovery device configured according to the present invention.
FIG. 3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 is a front view of a scraper used in a residual toner collecting apparatus configured according to the present invention.
[Explanation of symbols]
2: Image forming machine housing 3: Photoconductor drum 4: Charging corona discharger 5: Developing device 5a: Yellow toner developing unit 5b: Magenta developing unit 5c: Cyan toner developing unit 5d: Black toner developing Unit 6: Intermediate transfer member 7: Cleaning mechanism for photosensitive drum 8: Cleaning mechanism for intermediate transfer member 9: Laser unit 10: Secondary transfer roller 11: Conveying belt mechanism 12: Fixing unit 20: Residual toner collecting device 21 : Residual toner collecting container 30: Residual toner transport mechanism 31: Casing 310: Transport path 32: First casing member 33: Second casing member 321: Receiving part 322: Residual toner dropping path 331: Connecting part 332: Residual toner Drop passage 333: Connection portion 334: Residual toner discharge port 34: Conveying screw 341: Rotating shaft 42: The first spiral blade 343: second spiral blade 35, 36: bearing bush 40: Sweep roller 41: drive shaft 42: bearing bush 43: driving gear 44: bearing bush 45: scraper

Claims (1)

A cleaning mechanism that removes residual toner adhering to the peripheral surface of the toner image forming body, a residual toner collection container that stores residual toner removed by the cleaning mechanism, and residual toner removed by the cleaning mechanism A residual toner transport mechanism that transports the residual toner to a residual toner recovery container, the residual toner transport mechanism dropping the residual toner removed by the cleaning mechanism, the residual toner falling path, and the residual toner recovery In a residual toner recovery device of an image forming machine provided with a conveyance path that communicates with a container,
The residual toner transport mechanism includes a sweep roller disposed in the vicinity of a connection portion of the residual toner falling passage with the transport passage, an elliptical cross section, and a base end portion attached to an inner wall of the residual toner falling passage. Is provided with a scraper made of a flexible member disposed in pressure contact with the circumferential surface on the return direction side of the sweep roller, and the scraper is provided on a portion other than the contact portion with the sweep roller. Notches are formed,
A residual toner recovery device for an image forming machine.

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